共查询到19条相似文献,搜索用时 60 毫秒
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探讨了环糊精对美国西律对映体手性识别的机理,对毛细管电泳手性分离选择系数a值和环糊精包结常数的计算方法做了修正,计算了甲基化β环糊精与对映体形成包结络合物的稳定常数和手性分离过程中的热力学参数,并对由该方法计算的结果进行了分析,结果表明,环糊精对美西律对映体包结常数的大小顺序与它们的手性分离选择相相反,但是,手性分离过程中的焓变(△(△H)和熵变(△(△S))越大,手性分离选择性也越大,根据计算结 相似文献
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头孢噻吩手性对映体高效毛细管电泳分离 总被引:3,自引:0,他引:3
1 引 言头孢噻吩为第二代头孢菌素 ,对革兰氏阴性菌有较强的抗菌作用 ,且具有高度抗 β 内酰胺酶性质 ,可用于治疗敏感菌所致的尿路感染、呼吸道感染、腹膜炎、败血症、心内膜炎、皮肤和软组织感染等。但有胃肠道反应、白细胞减少、转氨酶升高、氮质血症和肾功能减退等副作用。目前国内使用的头孢噻吩对映体为含有两种对映异构体的外消旋体的混合物。对于头孢噻吩手性对映体高效毛细管电泳手性分离未见文献报道。因此 ,研究它们的手性分离不仅为此类手性药物提供了一种新的手性分离分析方法 ,而且对了解它们的药理作用、药效以及在临床… 相似文献
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毛细管区带电泳对手性药物盐酸美西律和盐酸异博定的对映体分离 总被引:1,自引:0,他引:1
应用环糊精-毛细管区带电泳体系对手性药物盐酸美西律和盐酸异博定的对映体分离进行了研究。结果表明, 在所研究的手性选择剂α-环糊精, β-环糊精, 二甲基-β-环糊精, 羟丙基β-环糊精和γ-环糊精中, 羟丙基β-环糊精对所研究的手性药物分离效果较好。对盐酸美西律和盐酸异博定的最佳羟丙基-β-环糊精浓度分别为30mmol/L和9mmol/L, 最佳缓冲溶液浓度为100mmol/L Tris-H3PO4(pH2.3)。向缓冲溶液中加入0.05%羟丙基纤维素(HPLC)可改善分离。盐酸美西律获得了接近基线的手性分离, 而盐酸异博定亦获得了较好的分离。 相似文献
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分别以2种天然环糊精(β、γ-环糊精)、2种常用的电中性环糊精衍生物(羟丙基-β-环糊精、二甲基-β-环糊精)和3种新型荷电环糊精衍生物(高取代磺酸基α、β、γ-环糊精)作为毛细管区带电泳手性添加剂,研究了环糊精的类型对6种手性药物对映体分离的影响.2种天然环糊精对所研究的手性药物均无手性识别能力,而环糊精经过衍生化后手性识别能力得到了很大的提髙,尤其是高取代磺酸基β-环糊精使6种手性药物均得到了基线分离.还考察了缓冲溶液的pH值和有机添加剂对手性分离的影响. 相似文献
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采用加压毛细管电色谱法,以羟丙基-β-环糊精作为手性选择剂,对美西律对映体进行手性分离。在优化的试验条件下,16 g·L~(-1)羟丙基-β-环糊精为手性选择剂,pH 2.5的乙腈与10 mmol·L~(-1)磷酸盐缓冲溶液以体积比1比1混合溶液为流动相,运行电压10 kV,毛细管柱温20℃,美西律对映体在4 min内成功分离,分离度为1.51。 相似文献
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本文报道一种以β-环糊精为手性分离试剂,毛细管电泳分离二氧异丙嗪对映体的新方法,详细研究了溶液pH值,β-环糊精浓度和电解质浓度等对二氧异丙嗪对异体分离的影响。 相似文献
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采用毛细管电泳法,以铜(Ⅱ)-L-异白氨酸为手性拆分剂,同时分离了氧氟沙星、洛美沙星、司帕沙星和加替沙星四种喹诺酮类药物对映体.考察了手性拆分剂的种类、配比和浓度,缓冲溶液的种类、浓度和pH值,有机添加剂的种类和用量,分离电压等试验条件对分离效果的影响.含8 mmol·L-1L-异白氨酸和4 mmol·L-1硫酸铜的pH 8.5的30 mmol·L-1硼酸钠-盐酸缓冲溶液中,氧氟沙星和加替沙星对映体实现分离;在含20 mmol·L-1 L-异白氨酸,10 mmol·L-1硫酸铜和乙腈(5+95)的pH 9.0的20 mmol·L-1的Tris-硼酸钠缓冲溶液中,司帕沙星、洛美沙星和加替沙星对映体同时实现完全分离. 相似文献
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毛细管电泳拆分苯磺酸氨氯地平及机理的探讨 总被引:7,自引:0,他引:7
采用羟丙基-β-环糊精(HP-β—CD)作为手性选择试剂对外消旋的苯磺酸氨氯地平进行了拆分,研究了环糊精种类,浓度,缓冲液的pH值以及添加剂对分离的影响,结果表明以羟丙基-β-环糊精为手性选择剂,短链的阳离子表面活性剂四乙基氯化铵为电渗流改性剂可以使苯磺酸氨氯地平实现基线分离,对拆分的机理进行了探讨。 相似文献
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《Analytical letters》2012,45(17):3177-3186
Abstract A capillary electrophoresis (CE) method for the simultaneous separation of geometry isomers and enantiomers of nateglinide was built. Several different dyclodextrin (CD) derivatives were tested for the chiral separation of nateglinide, and it was proved that ionic CDs [i.e., carboxymethy-β-CD (CM-β-CD) and sulphonic-β-CD (S-β-CD)] could show better chiral selectivity for both geometry isomers and enantiomers than the neutral CDs. The separation of geometry of both isomers and enantiomers of nateglinide was obtained by CE in a 75-µm i.d. × 60 cm (effective length 45 cm) fused-silica capillary at 11 kV voltage, while 30 mM phosphate (pH = 8.38) acted as running buffer and a mixture of 40 mM S-β-CD + 21 mM CM-β-CD served as chiral selector. The detective wavelength was set at 254 nm. 相似文献
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毛细管电泳在手性分离中的应用及进展 总被引:10,自引:0,他引:10
本文评述了近年来毛细管电泳在手性分离中的应用及进展,介绍了毛细管电泳分离手性对映射的数学模型、五种不同的分离模式及机理、七种常用的手性选择性类型及其在药学、环境和生命科学中的应用、研究中需优化的操作参数及其发展方向。 相似文献
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Xiaofeng Zhu Bingcheng Lin Andreas Jakob Ulrich Epperlein Bernhard Koppenhoefer 《Journal of separation science》1999,22(8):449-453
Orthogonal design and uniform design were used for the optimization of separation of enantiomers using 2,6-di-O-methyl-β-cyclodextrin (DM-β-CD) as a chiral selector by capillary zone electrophoresis. The concentration of DM-β-CD, buffer pH, running voltage, and capillary temperature were selected as variable parameters, their different effects on peak resolution were studied by the design methods. It was concluded that orthogonal design offers a rapid and efficient means for testing the importance of individual parameters and for determining the optimum operating conditions. However, for a large number of both factors and levels, uniform design is more efficient. The effect of addition of methanol and citric acid buffer on the separation of enantiomers was also examined. 相似文献
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Melania Crcu-Dobrin Gabriel Hancu Lajos Attila Papp Ibolya Fülp 《Molecules (Basel, Switzerland)》2022,27(17)
Mexiletine (MXL) is a class IB antiarrhythmic agent, acting as a non-selective voltage-gated sodium channel blocker, used in therapy as a racemic mixture R,S-MXL hydrochloride. The aim of the current study was the development of a new, fast, and efficient method for the chiral separation of MXL enantiomers using capillary electrophoresis (CE) and cyclodextrins (CDs) as chiral selectors (CSs). After an initial CS screening, using several neutral and charged CDs, at four pH levels, heptakis-2,3,6-tri-O-methyl-β-CD (TM-β-CD), a neutral derivatized CD, was chosen as the optimum CS for the enantioseparation. For method optimization, an initial screening fractional factorial design was applied to identify the most significant parameters, followed by a face-centered central composite design to establish the optimal separation conditions. The best results were obtained by applying the following optimized electrophoretic conditions: 60 mM phosphate buffer, pH 5.0, 50 mM TM-β-CD, temperature 20 °C, applied voltage 30 kV, hydrodynamic injection 50 mbar/s. MXL enantiomers were baseline separated with a resolution of 1.52 during a migration time of under 5 min; S-MXL was the first migrating enantiomer. The method’s analytical performance was verified in terms of precision, linearity, accuracy, and robustness (applying a Plackett–Burman design). The developed method was applied for the determination of MXL enantiomers in pharmaceuticals. A computer modeling of the MXL-CD complexes was applied to characterize host–guest chiral recognition. 相似文献
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